August, 1944 



Ross: Caddis Flies of Illinois 



289 



sternite black, as long as or longer 

 than the sternite; claspers with a 

 small, somewhat stalked cluster of 

 spicules upon mesal face at base, 



fig. 958 limnella Ross 



Sclerotized mesal projection ot sixth 

 sternite yellowish, only about halt 

 as long as the sternite; claspers with 

 a large, cushion-like pad of spicules 

 upon mesal face at base, fig. 959. . . 

 mexicana Banks 



3. Claspers angled and shaped like a 



boomerang, fig. 960 piroa n. sp. 



Claspers only slightly curved, broad 



and spatulate, fig. 961 



borealis Hagen 



Helicopsyche mexicana Banks 



The type of mexicana agrees perfectly 

 with males taken from near the type locality 

 of arizonensis. The females of this species 

 have the first antennal segment longer than 

 in related forms, which further identifies 

 the type of arizonensis. This difference, 

 however, is quite relative, and its use should 

 be based on actual comparison of specimens. 



In addition to various localities in Mex- 

 ico, this species is now known from springs 

 at Frijole, Texas, and from Oak Creek 

 Canyon, Arizona, as well as Nogales, Ari- 

 zona, the type locality of arizonensis. These 

 United States localities are all situated in 

 arid mountain country typical of large areas 

 in Mexico. 



Helicopsyche piroa new species 



This species appears most closely related 

 to borealis but may be readily separated 

 from it by the slender, L-shaped claspers. 



Male. — Length 6.5 mm. Head, body and 

 appendages straw color to yellowish brown, 



the wings with a few irregular, colorless 

 spots, and a short, colorless bar along the 

 cord ; rows of spines along middle legs, 

 black. General structure, including shape 

 of palps, wing venation, spur count, typical 

 for genus. Sixth sternite with a long, scle- 

 rotized black spur which is about as long 

 as the segment, slightly flattened and spatu- 

 late. Male genitalia as in fig. 960. Ninth 

 segment with ventral half reduced to a nar- 

 row band, the dorsal portion merging with 

 the tenth tergite. Tenth tergite about twice 

 as long as wide, fairly deep and with a 

 dorso-lateral ridge running its entire length 

 and bearing a regular row of medium 

 length setae. Claspers L-shaped, with a 

 short, narrow vertical base and a long, wide 

 horizontal apex which is rounded at tip ; at 

 the base of the mesal face is a short projec- 

 tion bearing a row of spicules along its api- 

 cal margin. Aedeagus cylindrical and slight- 

 ly curved, the apex subdivided into upper 

 and lower pairs of membranous folds. 



Female. — Similar in size, color and gen- 

 eral structure to male. Third and fourth 

 sternites with a central reticulate area. Re- 

 mainder of abdomen typical for genus. 



Holotype, male. — San Antonio, Texas, 

 along San Antonio River: Aug. 10, 1939, 

 Harold Alexander. 



Allotype, female. — Hacienda Vista Her- 

 mosa. Villa Santiago, Nuevo Leon, Mexico, 

 Hoogstraal & Knight. 



Paratypes. — Same data as for allotype, 

 6<5,29. 



In addition to the above records are 

 larvae of this species taken by Mr. Hoog- 

 straal in a spring at Sabinas Hidalgo, 

 Nuevo Leon, Mexico. This species makes 

 a case which is exactly like that of other 

 species in the genus. The larva is very simi- 

 lar in appearance to that of borealis. 



